Iridium(III) Catalyzed Oxidation of Leucine by Chloramine-T in Acidic Medium: A Kinetic and Mechanistic Study

Abstract

The present paper deals with the kinetics and mechanism of homogeneously Ir(III) chloride catalyzed oxidation of Leucine by chloramine-T (CAT) in perchloric acidic medium in the temperature range 30–45 °C. The reaction is carried out in the presence of mercuric acetate as a scavenger for chloride ion. The experimental results show first order kinetics with respect to the oxidant (CAT) and catalyst [Ir(III)] while positive effect with respect to substrate, i.e., Leucine was observed. The reaction shows negligible effect of [Hg(OAc)2], [H+] and ionic strength of the medium. Chloride ion positively influenced the rate of reaction. The various activation parameters were calculated from the rate measurments at different temperatures (30–45 °C). The reaction between chloramine-T and leucine in acid medium shows 1:1 stoichiometry. On the basis of kinetic studies, reaction stoichiometry and product analysis, a suitable mechanism has been proposed and rate law has been derived.